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1996 XB27 is classified as an Amor asteroid because its perihelion is less than 1.3 AU and does not cross Earth's orbit. The asteroid is on a low-eccentricity and low-inclination orbit between the orbits of Earth and Mars. This is within a region of stability where bodies may survive for the age of the Solar System, and hence it may have formed near its current orbit.[4]

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Kitt Peak National Observatory
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With 24 optical and two radio telescopes, it is the largest, most diverse gathering of astronomical instruments in the world. The observatory is administered by the National Optical Astronomy Observatory, Kitt Peak was selected by its first director, Aden B. Meinel, in 1958 as the site for an observatory under contract with the National Science Foundation and was administered by the Association of Universities for Research in Astronomy. The land was leased from the Tohono Oodham under a perpetual agreement, the second director was Nicholas U. The observatory sites are under lease from the Tohono Oodham Nation at the amount of a dollar per acre yearly. The principal instruments at KPNO are the Mayall 4 metre telescope, the WIYN3.5 metre telescope, and further 2.1 m,1.3 m,0.9 m, and 0.4 m reflecting telescopes. The McMath-Pierce Solar Telescope on the facilities is the largest solar telescope in the world, the ARO 12m Radio Telescope is also in the location. Kitt Peak is famous for hosting the first telescope used to search for near-Earth asteroids, additionally, there is the Advanced Observing Program for advanced amateur astronomers. This program allows for a one-on-one, full-night tour using any of the visitors center’s telescopes, guests may choose to do DSLR imaging, CCD imaging, or simply take in the sights with their eye to the telescope. Kitt Peaks Southeastern Association for Research and Astronomy Telescope was featured in the WIPB-PBS documentary, the project followed SARA astronomers from Ball State University to the observatory and featured time-lapse images from various points around Kitt Peak. Due to its elevation, the observatory experiences a much cooler and wetter climate throughout the year than most of the Sonoran desert

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Minor planet
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A minor planet is an astronomical object in direct orbit around the Sun that is neither a planet nor exclusively classified as a comet. Minor planets can be dwarf planets, asteroids, trojans, centaurs, Kuiper belt objects, as of 2016, the orbits of 709,706 minor planets were archived at the Minor Planet Center,469,275 of which had received permanent numbers. The first minor planet to be discovered was Ceres in 1801, the term minor planet has been used since the 19th century to describe these objects. The term planetoid has also used, especially for larger objects such as those the International Astronomical Union has called dwarf planets since 2006. Historically, the asteroid, minor planet, and planetoid have been more or less synonymous. This terminology has become complicated by the discovery of numerous minor planets beyond the orbit of Jupiter. A Minor planet seen releasing gas may be classified as a comet. Before 2006, the IAU had officially used the term minor planet, during its 2006 meeting, the IAU reclassified minor planets and comets into dwarf planets and small Solar System bodies. Objects are called dwarf planets if their self-gravity is sufficient to achieve hydrostatic equilibrium, all other minor planets and comets are called small Solar System bodies. The IAU stated that the minor planet may still be used. However, for purposes of numbering and naming, the distinction between minor planet and comet is still used. Hundreds of thousands of planets have been discovered within the Solar System. The Minor Planet Center has documented over 167 million observations and 729,626 minor planets, of these,20,570 have official names. As of March 2017, the lowest-numbered unnamed minor planet is 1974 FV1, as of March 2017, the highest-numbered named minor planet is 458063 Gustavomuler. There are various broad minor-planet populations, Asteroids, traditionally, most have been bodies in the inner Solar System. Near-Earth asteroids, those whose orbits take them inside the orbit of Mars. Further subclassification of these, based on distance, is used, Apohele asteroids orbit inside of Earths perihelion distance. Aten asteroids, those that have semi-major axes of less than Earths, Apollo asteroids are those asteroids with a semimajor axis greater than Earths, while having a perihelion distance of 1.017 AU or less. Like Aten asteroids, Apollo asteroids are Earth-crossers, amor asteroids are those near-Earth asteroids that approach the orbit of Earth from beyond, but do not cross it

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Amor asteroid
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The Amor asteroids are a group of near-Earth asteroids named after the asteroid 1221 Amor. They approach the orbit of Earth from beyond, but do not cross it, most Amors cross the orbit of Mars. The two moons of Mars, Deimos and Phobos, may be Amor asteroids that were captured by Marss gravity, the most famous member of this group is 433 Eros, which was the first asteroid to be orbited and then landed upon by a human probe. There are three general criteria which an asteroid must meet to be considered a member of the Amor asteroid class, to be considered near, the asteroid must come closer to Earth than to any other major planet. The closest planet to Earth is Venus, which can come as close as 0.27 AU, therefore, an Amor asteroid must come within 0.30 AU of Earths orbit. The asteroids orbit must be outside the orbit of Earth, asteroids that come close to Earth whose orbits are inside Earths orbit are considered Apohele asteroids. The asteroids orbit must not cross Earths orbit, the most commonly used definition of this is that it never orbits closer to the Sun than Earths average distance from the Sun. A more strict definition is that at any point along the asteroids orbit and this takes into consideration the fact that Earths orbit ranges between 0.983 and 1.016 AU from the Sun. It is more difficult to sort out the Amor asteroids from the non-Amor asteroids using this definition, however. These three criteria boil down to a single test for membership, If an asteroid has a perihelion between 1.000 AU and 1.300 AU, it is an Amor asteroid. Any asteroid with this trait is considered an Amor-class asteroid, regardless of its axis, eccentricity, aphelion, inclination, physical properties, orbital stability. An asteroid belongs to the Amor group if, Its orbital period is greater than one year and this is equivalent to saying that its semi-major axis is greater than 1.0 AU. Its orbit does not cross Earths orbit and that is, its lowest point is higher than Earths highest point. It is an object, that is, its perihelion distance q <1.3 AU. In summary, a >1.0 AU and 1.017 AU < q <1.3 AU, there are 6051 Amor asteroids currently known. 960 of them are numbered, and 73 of them are named, Amor asteroids can be partitioned into four subgroups, depending on their average distance from the Sun. The Amor I subgroup consists of Amor asteroids whose semi-major axes are in between Earth and Mars and that is, they have a semi-major axis between 1.000 and 1.523 AU. Less than one fifth of Amor asteroids belong to this subgroup, Amor I asteroids have lower eccentricities than the other subgroups of Amors

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Near-Earth object
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A near-Earth object is any small Solar System body whose orbit brings it into proximity with Earth. By definition, a solar system body is a NEO if its closest approach to the Sun is less than 1.3 astronomical unit and it is now widely accepted that collisions in the past have had a significant role in shaping the geological and biological history of the Earth. NEOs have become of increased interest since the 1980s because of increased awareness of the potential danger some of the asteroids or comets pose, and mitigations are being researched. In January 2016, NASA announced the Planetary Defense Coordination Office to track NEOs larger than 30 to 50 meters in diameter and coordinate an effective threat response, NEAs have orbits that lie partly between 0.983 and 1.3 AU away from the Sun. When a NEA is detected it is submitted to the IAUs Minor Planet Center for cataloging, some NEAs orbits intersect that of Earths so they pose a collision danger. The United States, European Union, and other nations are currently scanning for NEOs in an effort called Spaceguard. In the United States and since 1998, NASA has a mandate to catalogue all NEOs that are at least 1 kilometer wide. In 2006, it was estimated that 20% of the objects had not yet been found. In 2011, largely as a result of NEOWISE, it was estimated that 93% of the NEAs larger than 1 km had been found, as of 5 February 2017, there have been 875 NEAs larger than 1 km discovered, of which 157 are potentially hazardous. The inventory is much less complete for smaller objects, which still have potential for scale, though not global. Potentially hazardous objects are defined based on parameters that measure the objects potential to make threatening close approaches to the Earth. Mostly objects with an Earth minimum orbit intersection distance of 0.05 AU or less, objects that cannot approach closer to the Earth than 0.05 AU, or are smaller than about 150 m in diameter, are not considered PHOs. This makes them a target for exploration. As of 2016, three near-Earth objects have been visited by spacecraft, more recently, a typical frame of reference for looking at NEOs has been through the scientific concept of risk. In this frame, the risk that any near-Earth object poses is typically seen through a lens that is a function of both the culture and the technology of human society, NEOs have been understood differently throughout history. Each time an NEO is observed, a different risk was posed and it is not just a matter of scientific knowledge. Such perception of risk is thus a product of religious belief, philosophic principles, scientific understanding, technological capabilities, and even economical resourcefulness.03 E −0.4 megatonnes. For instance, it gives the rate for bolides of 10 megatonnes or more as 1 per thousand years, however, the authors give a rather large uncertainty, due in part to uncertainties in determining the energies of the atmospheric impacts that they used in their determination

The ecliptic is the circular path on the celestial sphere that the Sun appears to follow over the course of a year; it …

The plane of Earth's orbit projected in all directions forms the reference plane known as the ecliptic. Here, it is shown projected outward (gray) to the celestial sphere, along with Earth's equator and polar axis (green). The plane of the ecliptic intersects the celestial sphere along a great circle (black), the same circle on which the Sun seems to move as Earth orbits it. The intersections of the ecliptic and the equator on the celestial sphere are the vernal and autumnal equinoxes (red), where the Sun seems to cross the celestial equator.

The astronomical unit (symbol: au or ua) is a unit of length, roughly the distance from Earth to the Sun. However, that …

The red line indicates the Earth–Sun distance, which on average is about 1 astronomical unit.

Transits of Venus across the face of the Sun were, for a long time, the best method of measuring the astronomical unit, despite the difficulties (here, the so-called "black drop effect") and the rarity of observations.

The astronomical unit is used as the baseline of the triangle to measure stellar parallaxes (distances in the image are not to scale).

In celestial mechanics, the mean anomaly is an angle used in calculating the position of a body in an elliptical orbit …

Area swept out per unit time by an object in an elliptical orbit (grey) and by an imaginary object in a circular orbit (red) which completes its orbit in the same period of time. Both sweep out equal areas in equal times, but the angular rate of sweep varies for the elliptical orbit and is constant for the circular orbit. Shown are mean anomaly and true anomaly for two units of time.